Let $\stackrel{\mathbb{J}}{\mathrm{a}}=4 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}$ and $\stackrel{\mathrm{b}}{\mathrm{b}}=3 \hat{\mathrm{i}}-4 \hat{\mathrm{j}}+5 \hat{\mathrm{k}}$ and $\stackrel{n}{\mathrm{c}}$ is a vector such that $\stackrel{\mathbb{Z}}{\mathrm{c}} \cdot(\mathrm{a} \times \mathrm{b})+25=0, \stackrel{\mathbb{W}}{\mathrm{c}} \cdot(\hat{\mathrm{i}}+\hat{\mathrm{j}}+\hat{\mathrm{k}})=4$ and projection of $\stackrel{c a}{c}$ on $\stackrel{a}{a}$ is 1 , then the projection of $\stackrel{c}{c}$ on $\stackrel{b}{b}$ equals: